public class Example4_20{
  public static void main(String[] args) {
    char a[]={'a','b','c','D','E','F'};
    for(int i=0;i<a.length;i++){
      if(Character.isLowerCase(a[i]))
      a[i]=Character.toUpperCase(a[i]);
      else if(Character.isUpperCase(a[i]))
      a[i]=Character.toLowerCase(a[i]);
    }
    for(int i=0;i<a.length;i++)
    System.out.println(""+a[i]);
  }
}
